hi how can i use FLUENT to claulate erosion rate in metals parts.

Yes. There is a tutorial about that

you need iterate your case file until will converge. next to it, in the define-model-phase discrete, you need turno on the iteration with continuous phase and set some kind of injection. In the fluent tutorial you can search the explain about the steps that you should follow.

which tutorial are u referring to?

Regards Rajeev